1. Field of the Invention
The present invention relates to a process for producing crystallographic oriented oxide thin films having an NaCl-type structure, a spinel structure or a Wurtzite structure used as a buffer layer to obtain a functional oxide thin film such as a superconductive oxide thin film or a ferroelectric thin film, and a chemical vapor deposition apparatus used therefor.
2. Description of the Prior Art
Studies are actively conducted to produce crystallographic oriented oxide thin films of an NaCl-type structure, a spinel structure or a Wurtzite structure on a low-cost substrate such as a glass substrate to be used as a buffer layer to obtain a functional oxide thin film such as a superconductive oxide thin film or a ferroelectric thin film. In particular, a plasma-enhanced chemical vapor deposition method using a metal complex as a starting material can provide crystallographic oriented oxide thin films of an NaCl-type structure, a spinel structure or a Wurtzite structure regardless of the kind of the substrate. This method is to generate a high frequency plasma between parallel plate electrodes so as to provide a mixed gas including material gas (gas of a .beta.-diketone metal complex) and oxide gas to a substrate located on the surface of one of the electrodes like shower (Yu-Wen Zhao and H. Suhr: Appl. Phys. A 54 (1992) 451-454).
However, by the above mentioned conventional method, due to the difficulty in providing a great amount of the material gas uniformly onto a large area of the substrate due to low vapor pressure of .beta.-diketone metal complex used as the starting material, and difficulty in having a laminar flow of the gas on the surface of the substrate, it has been difficult to produce a high-quality crystallographic oriented oxide thin film uniformly in a large area at a high speed.
In order to solve the above mentioned problems of conventional arts, an object of the present invention is to provide a process for producing produce crystallographic oriented oxide thin films of an NaCl-type structure, a spinel structure or a Wurtzite structure used as a buffer layer to obtain a functional oxide thin film such as a superconductive oxide thin film and a ferroelectric thin film uniformly in a large area at a high speed, and a chemical vapor deposition apparatus used therefor.